Combining memory with different speeds?

[Dispect]

Hi guys, I currently have this on my rig. 

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231428

 

I wanna get 2 more sticks so I can get my RAM to 16GB. However, that particular pair seems to be backordered throughout Canada where I live.

http://www.ncix.com/detail/g-skill-ripjawsx-f3-17000cl11d-8gbxl-8gb-2x4gb-cd-61213.htm

So my question is, can I get the same brand/series of RAM but different speeds at combine them in in my rig such as these ones?

 

Will that affect anything? 

Thanks!

[RZeroX]

All your ram will run at the lowest speed ram so lets say 1600 is the lowest and you have ram which is 1866 all the ram sticks will run at 1600

[SIGSEGV]

If they are at different speeds I believe most motherboards will set the clock for all of the RAM to the slowest clocked RAM you put on your motherboard

[-rascal-]

You will have to run all 4 sticks at the slowest denominator -- in your case, your DDR3-1600MHz kit settings:

• 1600MHz
• 9-9-9-24 Timings
• 1.5V

You could try to overclock your 1600MHz kit to 1866MHz or 2133MHz (and tinker with the timings), but don't count on it 100% that it will succeed.

[Priller]

Increase voltage to 1.6V and try 10-11-10-30 at 1866.